Panasonic KX-T7601Factory ServicedIncludes 90 Day WarrantyThe Panasonic KX-T7601 USB expansion card is used with KX-T7636 and KX-T7633 telephones. This USB expansion card is required for use with PC Phone KX-TDA0350. The KX-T7601-B includes 6 foot USB cable and a CD containing free 90 day trial phone software. Max one USB module per telephone can be used.